JPS6215649B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a draft device in spinning.

A draft device in a spinning machine is extremely important because it makes the fiber bundle a predetermined thickness and also stretches and straightens each fiber one by one. Drafting machines and bobbiners that apply thick fiber bundles are already performing drafting at high speeds of several hundred meters/minute. Furthermore, with recent remarkable technological advances, innovative spinning methods such as bundle spinning and self-twist spinning have been put into practical use, and spinning speeds of several hundred meters per minute have been achieved.
1 and 2 are so-called draft devices,
It is formed from the front rollers of the top roller 1 and the bottom roller 1', which have faster surface speed than the back roller consisting of the top roller 3 and the bottom roller 3', or the cradle 2,
2′, but in this device,
When the front rollers 1, 1' rotate, an accompanying air current is generated on the roller surface. Here, as the roller surface speed increases, the accompanying air currents from the top roller and bottom roller collide with each other on the roller nip line and escape in parallel to the rollers. FIG. 2 is a schematic diagram showing the state of this accompanying airflow. As shown in this figure, accompanying airflows a and a' are generated by the rotation of the front rollers 1 and 1', collide with each other near the nip line between the top and bottom rollers, and flows parallel to the rollers b,
It becomes b′ and escapes outside the roller. Here, the fiber bundle 4 is thinner than that of a drawing machine or a bobbiner, the entanglement force between the fibers is small, and it is very susceptible to the influence of air currents from the outside. The surface speed of front rollers 1 and 1' is 50
At m/min or more, the accompanying airflows b and b' become quite large and begin to affect the thin fiber bundle 4, which has a weak entanglement force. That is, among the thin fiber bundles 4, the peripheral fibers with particularly weak entanglement force are affected by the airflow b,
Begins to ride b′. Since the fibers carried by the air currents b and b' protrude from the central fiber bundle, when they become yarn, they become fluff that protrudes from the yarn body. Furthermore, the surface speed of the front roller is 100m/
At high speeds of more than 1 minute, a considerable number of fibers will be caught in the accompanying air current, some of which will become fluff and fly away, resulting in a very fluffy yarn, and the draft will not occur normally, causing the yarn to become fluffy and fluffy. The unevenness becomes larger. Such countermeasures include reducing the diameter of the roller to reduce the accompanying airflow, or devising a collector to make it difficult for airflow to enter. However, the former is easy to wrap around the roller,
The latter method is not preferable because the collector is easily damaged due to the high speed and the collector is easily drawn into the roller, causing damage to the roller. As a solution to these problems,
In the spinning device seen in the −28250 publication,
An apertured roll is used on the bottom side of the front roller (delivery roller), and there is a gap at the nip point that does not affect the nip, allowing the accompanying airflow to escape to the front side and preventing the negative effects of the accompanying airflow. A high-speed draft of /min is obtained. However, since it is a special roller, there is a problem in equipment cost.

On the other hand, in the device described in Japanese Patent Publication No. 50-20168, a high-speed draft of 500 m/min or more is achieved by using a conduit in the draft zone between the back crawler and the front roller and passing high-speed air through the conduit. There is. However, although this method is effective for thick slivers of fiber bundles,
At speeds below 400 to 500 m/min, which is the practical speed for spinning, etc., it is affected by the accompanying airflow and the exhaust airflow from the conduit.
Furthermore, since the fiber bundle entering the spinning process is extremely thin, it is easily affected by these air currents, and it is difficult to produce uniform yarn using this method.

The present invention solves these drawbacks, completely suppresses the accompanying airflow, and performs stable drafting at high speeds of several hundred meters/minute without disturbing the fiber bundles with extremely small entanglement forces, which is no different from that at low speeds. , which provides the production of uniform spun yarn with a uniform surface and less fuzz.

A feature of the draft device of the present invention is that a thin plate is provided near the surface of the front roller, which is a problem with accompanying airflow, to eliminate direct contact with surrounding air, and also prevents accompanying airflow carried from other parts. , stop there, and pass the fiber bundle (nip line part)
In addition, it prevents the accompanying airflow from the rollers and suppresses the adverse effects of the accompanying airflow.According to the findings of the present inventors, even a thin fiber bundle with a few tens of fibers can be processed at high speeds of several hundred meters/minute. This is a revolutionary feature that allows for stable drafting.

Next, the present invention will be explained in detail with reference to the drawings. In FIG. 3, 1 is a schematic diagram of the device of the present invention, and 2 is a schematic diagram of the device of the present invention.
It is a diagram seen from the side.

In these figures, 1 and 1' are front rollers rotating at high speed, 2 and 2' are cradles, 3 and 3' are back rollers, and 4 is a fiber bundle being drafted. Reference numerals 5 and 5' denote thin metal airflow suppressing plates whose tips are in contact with the front rollers 1 and 1', and are installed approximately symmetrically to the top and bottom rollers. The tip is close to the nip point, and the opening interval l of the portion through which the fiber bundle passes is preferably 1 to 30 mm, preferably 10 to 20 mm. 6,6' is
This is a holder for the airflow suppression plates 5, 5'. The airflow suppressing plates 5, 5' have a thickness of 0.10 to 0.50 mm, preferably 0.20 to 0.50 mm.
A thin metal plate of 0.30 mm is good; if it is thinner than 0.10 mm, the contact pressure will be too small. The material is preferably a steel plate, a phosphor bronze plate, etc., which have appropriate elasticity.

Next, we will discuss the effect.

Since there are airflow suppression plates 5, 5' in contact with the rollers near the nip point of the rollers 1, 1', there is no contact between the roller surface and the surrounding air, so even if the rollers rotate at high speed, there will be no entrainment. Almost no airflow occurs. Further, the accompanying airflow generated far away from the nip point is also blocked by the airflow suppression plates 5, 5' and cannot reach the nip portion, so that the fiber bundle 4 is hardly affected by disturbance from the outside. This allows for stable drafting without any fuzz, producing uniform yarn with little fuzz.

Example In the drafting device shown in FIG. 3 of the present invention, a yarn forming section according to Japanese Patent Publication No. 43-28250 was provided as a yarn forming section, and binding yarn was spun.

The spinning conditions at this time are as shown in the table below.

Material: Polyester Fineness: 1.5d, average fiber length: 85mm Roving thickness: 1.0s Draft magnification: 63.0x Twist shrinkage: 5.0% Spinning count: 100/1 (90d) Spinning speed: 350m/min Also, air flow The suppression plate is made of phosphor bronze and has a thickness of 0.20mm.
A vertical distance l=15 mm was used. In the spinning state, there is no significant disorder of the fibers at the nip, and the obtained yarn is uniform with little fluff on the surface.
The Worcester u% was also 14.7%, with little yarn unevenness.

On the other hand, spinning was carried out under the same conditions as above without using the airflow suppression plate. At this time, the spinning speed is 350
m/min, most of the fibers were pushed out from the front roller sideways by the entrained airflow and were not turned into yarn, and the maximum speed at which the yarn could be spun was 250 m/min. However, the surface of the yarn at this time was abnormally fluffy, and the yarn was uneven at a Worcester U% of 18.3%, which was problematic for practical use.Fibers that protruded from the roller became fluff and clogged the nozzle. occurred and was in poor health.

[Brief explanation of the drawing]

FIG. 1 shows a conventional draft device, FIG. 2 is a schematic diagram showing the flow direction of accompanying airflow at the front roller inlet, and FIG. 3 shows a draft device of the present invention. In these figures, 1 and 1' are front rollers, 3 and 3' are back rollers,
5 and 5' are airflow suppression plates, and 6 and 6' are airflow suppression plate holders.

Claims (1)

[Claims] 1. Provide curved plates along the rollers near the surfaces of the top roller and bottom roller, respectively,
A high-speed draft device characterized in that at least a portion of the curved plate is brought into contact with the surface of the roller.